Restarting from bootable SSD

[davidgrier]

Hi there,
I have a 2017 iMac 27" with a 2T fusion drive and 40GB RAM. It was becoming slower and slower so I created a bootable SSD which I now use as my main drive and it's much faster with most things. I know it might be considered obsolete now but am waiting for M4 Macs.
But although I can boot into the SSD when the computer is off using the option key to select it, whenever I do a restart the option to choose SSD is not present and despite selecting the SSD as the startup disc in settings, the restart always defaults to the native Macintosh HD. I've attached a screenshot of the discs from disk utility - have I managed to mess up the containers / volumes on the SSD? is there a simple solution?
Many thanks in anticipation.
David

 

[pshufd]

Have you set the startup drive in both operating systems?

 

[davidgrier]

Thanks for the suggestion but startup drive is set to SSD in both systems. Only have option to boot to SSD when starting from cold but not when restarting.
I can live with this but it would be nice to resolve this irritation.
David

 

[niteflyr]

1. What happens when you just do a normal cold start? If you have set the SSD as the startup disc, you should not need to Option boot from cold start and select the SSD.

2. Perhaps the SSD is disconnecting during a restart vs a shutdown/cold start. Can you see the SSD in disk utility after a re-start and it defaults to Macintosh HD?

 

[davidgrier]

A normal cold start booted straight into the external SSD this morning but any attempt to restart defaults to the MacHD (the SSD does not show as an option if I Option-Restart).
The SSD appears to be visible in disk utility after it boots from the HD - see attached.
And the SSD is selected as the start-up disc on both drives.
David

 

[Fishrrman]

I don't have "the answer" for you.

But I saw something posted just yesterday that may offer a modest "workaround".

There's a terminal command that will invoke the startup manager with EVERY boot:
sudo nvram manufacturing-enter-picker=true

(password will be required, then restart)

To go back to "normal":
sudo nvram -c

(again, password will be required, then restart)

What this should do:
With every cold boot or restart, you should see the startup manager appear.
Then you can probably just hit the right-arrow key once, and hit return, to boot to the external SSD.

Again, this doesn't "solve" the problem, but it "smooths the way" to getting booted to the external SSD each time -- without any "false boots" to the internal fusion drive.

(you don't happen to play a little acoustic guitar, by any chance...?)

 

[davidgrier]

Thanks for this - it does as you say and avoids need to hold down Option key on cold start. Sadly no effect on using the restart which always defaults to HD, even when Option key used.
I think I will live with this as a small price to pay as in all other respects the iMac (after transferring all to the SSD and booting from it) is much faster than before and almost crash free.
Although I cannot upgrade OS any more (on Ventura) there's still a year of security patches etc. before it is totally unsupported.

(I did try the mandolin a few years ago but the results were worse than being made to listen to Vogon poetry)

 

[Macky-Mac]

I had a somewhat similar problem when I first started using an external SSD as my boot drive on a late 2014 iMac.

How is your external drive connected to your iMac? I've had to connect my external SSD to a powered hub instead of using the built in port on the back of the iMac.....and now it works fine.

 

[davidgrier]

That’s a thought - thanks. It’s plugged directly into the back of the iMac - USB3 or Thunderbolt - not sure which it is but not using the ’old’ type of USB. I haven’t got a hub but may look into this. Did you get the hub specifically to solve this problem or was it an unintended but fortuitous outcome?

 

[Macky-Mac]

That’s a thought - thanks. It’s plugged directly into the back of the iMac - USB3 or Thunderbolt - not sure which it is but not using the ’old’ type of USB. I haven’t got a hub but may look into this. Did you get the hub specifically to solve this problem or was it an unintended but fortuitous outcome?

The hub was bought in the desperate hope it would solve the problem.

I'd reached the point where I was guessing that for some unknown reason the external SSD wasn't getting enough power in time for the boot process to recognize it.....this was two years ago and I haven't had the problem since I started using the hub.

 

[davidgrier]

Thanks - I think I'll try this.

 

[Fishrrman]

Sometimes it's the enclosure.
Sometimes it's the cable.
Sometimes it's the drive.
Sometimes it's a combination of factors.

A 2017 iMac has USB3.1 gen2 ports (USBc form factor).
With USB3.1 gen2 you should get read speeds up around 900MBps or even better.

So... you'd want either an nvme SSD (in a USB3.1 gen2 enclosure)
or
A "ready-to-use" drive of some kind (such as a Crucial x9).

I wouldn't mess with thunderbolt, unless you already have a thunderbolt drive and connecting cable that is giving you speeds higher than you could get with USB3.1 gen2.

Also, you want a high-speed charging USBc connecting cable that's rated for 10gb speeds, not the ordinary 5gb.

David, what kind of reads are you getting now, once booted up?
(I like "AJA system test lite" for this)

 

[davidgrier]

Thanks - the speeds I get are 800-900 read and 400-500 write depending on the simulated file size I put in - see attached/
The external SSD is a

LaCie Rugged Mini SSD 2TB​

But I'm not sure if a lower write speed compared to the read speed is expected. If not then it might be helped by a powered hub